(1) Field of the Invention
The present invention relates to a method for the preparation of a laminated material mainly annual lignocellulosic stalks and a laminated material produced by the method, more particularly to a method for the preparation of a laminated material used for various building materials, such as heat insulating materials, sound absorbing materials, building materials for fixture, furniture materials or structural building materials and also for display materials or materials for handicrafts.
(2) Description of the Related Art
Building materials other than plywood and veneer include wood based materials, such as particleboard, fiberboard, and synthetic resin foam made of polystyrene or polyethylene.
Particleboard is made by combining wood chips and a synthetic resin adhesive mixture with heat and pressure. Fiberboard is made by compressing wood and other vegetable fibers. Particleboard and fiberboard do not suffer from aeolotropy in practical use and lack the shortcomings of natural materials, such as knots, rot, dimensional distortion, and warping. Furthermore, one can select the desired specific gravity, thickness, and size of these boards according to use. Synthetic resin foam, being light and having an excellent heat insulating property as well as good workability, is widely used as a heat insulating material in building construction.
However, because the main material of the above-mentioned wood based materials is natural wood, the supply is limited and may not be sufficient to meet demand in the future. Thus, there is a fear that wood based materials will become expensive. Furthermore, particleboard, fiberboard, and synthetic resin foam have low strength in comparison with materials like plywood. Even if made dense, they do not have the strength required for structural materials.
An object of this invention is to provide a method for the preparation of a laminated material based on cheap, abundant materials, i.e., annual lignocellulosic stalks.
Another object of this invention is to provide a method for the preparation of a laminated material having a strength equal to or higher than that of plywood on the market.
A further object of this invention is to provide a method for the preparation of a laminated material having high sound absorbing and heat insulating properties.
A still further object of this invention is to provide a method for the preparation of a laminated material from a low to high specific gravity.
An additional object of this invention is to provide a laminated material in the form of a board made by the method.